1. Field of the Invention
The invention relates to semiconductor technology and more particularly to a lens module.
2. Description of the Related Art
FIG. 1A is a cross-section of a conventional lens module. In FIG. 1A, a glass substrate 1 is utilized for formation of a lens module 10. A plurality of lens modules 10 may be formed on the glass substrate 1. The lens module 10 comprises a first lens part 11, a second lens part 12 and a glass portion 13, wherein the glass substrate 1 is between the first and second lens parts 11 and 12. The first and second lens parts 11 and 12 are formed by transparent polymer.
FIG. 1B is a cross-section of the conventional lens module 10 and molding dice 20 and 30 for formation of the lens module 10. The molding die 20 comprises a pattern 21 for formation of the first lens part 11 of the lens module 10, and the molding die 30 comprises a pattern 31 for formation of the second lens part 12 of the lens module 10.
The lens module 10 is formed by the subsequent steps. First, a lens material (not shown) is dispensed on a first surface 1a of the glass substrate 1. Then, the molding die 20 is disposed on the first surface 1a of the glass substrate 1, imprinting and shaping the lens material utilizing the pattern 21, followed by curing the shaped lens material to complete the first lens part 11 of the lens module 10. Next, the same lens material (not shown) is dispensed on the pattern 31 of the molding die 30. Then, the combination of the glass substrate 1 and the molding die 20 is moved toward the molding die 30, and a second surface 1b, opposite to the surface 1a, of the glass substrate 1 contacts the pattern 31 of the molding die 30 to imprint and shape the lens material on the pattern 31 of the molding die 30, followed by curing the shaped lens material to complete the second lens part 12 of the lens module 10. Thus, the lens module 10 is complete. Finally, the glass substrate 1 with the lens module 10 and the molding dice 20 and 30 are separated.
As described, there are many process steps required for fabrication of the lens module 10. The first lens part 11 of the lens module 10 is twice cured, and thus, may be over hardened. At least two problems may occur due to over hardening of the first lens part 11 of the lens module 10. One is shrinkage variation of the first lens part 11, and the other is color yellowing of the first lens part 11. These problems have the potential to negatively affect the optical performance of the lens module 10. Further, the lens module 10 is not homogeneous because the first and second lens parts 11 and 12 are polymer, and the glass portion 13 is glass. The polymer and glass have different refractive indexes, and light total reflection occurs in the interface therebetween. Thus, there are two glass/polymer interfaces in the lens module 10, negatively affecting light transmittance thereof. Moreover, further process steps are required for formation of dam structures (not shown) and/or light shields (not shown) for the lens module 10.